Wörner, Gerhard

[["dc.bibliographiccitation.artnumber","PII S0040-1951(01)00212-8"],["dc.bibliographiccitation.firstpage","183"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Tectonophysics"],["dc.bibliographiccitation.lastpage","198"],["dc.bibliographiccitation.volume","345"],["dc.contributor.author","Worner, G."],["dc.contributor.author","Uhlig, D."],["dc.contributor.author","Kohler, I."],["dc.contributor.author","Seyfried, H."],["dc.date.accessioned","2018-11-07T10:31:58Z"],["dc.date.available","2018-11-07T10:31:58Z"],["dc.date.issued","2002"],["dc.description.abstract","The geological record of the Western Andean Escarpment (WARP) reveals episodes of uplift, erosion, volcanism and sedimentation. The lithological sequence at 18degreesS comprises a thick pile of Azapa Conglomerates (25-19 Ma), an overlying series of widespread rhyodacitic Oxaya Ignimbrites (up to 900 m thick, ca. 19 Ma), which are in turn covered by a series of mafic andesite shield volcanoes. Between 19 and 12 Ma, the surface of the Oxaya Ignimbrites evolved into a large monocline on the western slope of the Andes. A giant antithetically rotated block (Oxaya Block, 80 kmx20 km) formed on this slope at about 10-12 Ma and resulted in an easterly dip and a reversed drainage on the block's surface. Morphology, topography and stratigraphic observations argue for a gravitational cause of this rotation. A \"secondary\" gravitational collapse (50 km(3)), extending 25 kin to the west occurred on the steep western front of the Oxaya Block. Alluvial and fluvial sediments (11-2.7 Ma) accumulated in a half graben to the east of the tilted block and were later thrust over by the rocks of the escarpment wall, indicating further shortening between 8 and 6 Ma. Flatlying Upper Miocene sediments (<5.5 Ma) and the 2.7 Ma Lauca-Perez Ignimbrite have not been significantly shortened since 6 Ma, suggesting that recent uplift is at least partly caused by regional tilting of the Western Andean slope. (C) 2002 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0040-1951(01)00212-8"],["dc.identifier.isi","000174882100010"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11235"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44237"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0040-1951"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","CC BY-NC-ND 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/3.0/"],["dc.title","Evolution of the West Andean Escarpment at 18 degrees S (N. Chile) during the last 25 Ma: uplift, erosion and collapse through time"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","961"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Bulletin of Volcanology"],["dc.bibliographiccitation.lastpage","976"],["dc.bibliographiccitation.volume","70"],["dc.contributor.author","Pabst, Sonja"],["dc.contributor.author","Woerner, Gerhard"],["dc.contributor.author","Civetta, Lucia"],["dc.contributor.author","Tesoro, Roberto"],["dc.date.accessioned","2018-11-07T11:13:17Z"],["dc.date.available","2018-11-07T11:13:17Z"],["dc.date.issued","2008"],["dc.description.abstract","The Campi Flegrei (Campanian Region, Italy) experienced two cataclysmic caldera-forming eruptions which produced the Campanian Ignimbrite (39 ka, CI) and the Neapolitan Yellow Tuff (15 ka, NYT). We studied the minor eruptions before both these large events to understand magma chamber evolution leading towards such catastrophic eruptions. Major, trace element, and Sr and Nd isotope compositions of pre-Campanian Ignimbrite and pre-Neapolitan Yellow Tuff products define distinct geochemical groups, which are here interpreted as distinct magma batches. These batches do not show any transitional trend towards the CI and NYT eruptions. The CI and NYT systems are decoupled geochemically and isotopically. At least one of the pre-CI and one of the pre-NYT erupted magma batches qualifies as mixing endmembers for the large CI and NYT eruptions, and thus, must have been stored in reservoirs for some time to remain available for the CI and NYT eruptions. The least evolved, isotopically distinct magma compositions that are typical of the last phases of the NYT and CI eruptions did not occur before caldera-forming events. Based on the new data, we propose the following scenario: Multiple magma chambers with distinct compositions existed below the Campi Flegrei before the CI and NYT eruptions and remained generally separated for some time unless new magma was recharged. In each case, one of the residing magma reservoirs was recharged by a new large-volume magma input of intermediate composition from a deeper differentiating magma reservoir. This may have triggered the coalescence of the previously separated reservoirs into one large chamber which fed the cataclysmic caldera-forming eruption. Large magma chambers in the Campi Flegrei may therefore be ephemeral features, interrupted by periods of evolution in individual, separated magma reservoirs."],["dc.identifier.doi","10.1007/s00445-007-0180-z"],["dc.identifier.isi","000257368200004"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/6755"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53853"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0258-8900"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Magma chamber evolution prior to the Campanian Ignimbrite and Neapolitan Yellow Tuff eruptions (Campi Flegrei, Italy)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","659"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Contributions to Mineralogy and Petrology"],["dc.bibliographiccitation.lastpage","687"],["dc.bibliographiccitation.volume","159"],["dc.contributor.author","Volynets, Anna O."],["dc.contributor.author","Churikova, Tatiana G."],["dc.contributor.author","Woerner, Gerhard"],["dc.contributor.author","Gordeychik, Boris N."],["dc.contributor.author","Layer, Paul"],["dc.date.accessioned","2018-11-07T08:43:29Z"],["dc.date.available","2018-11-07T08:43:29Z"],["dc.date.issued","2010"],["dc.description.abstract","New (40)Ar/(39)Ar and published (14)C ages constrain voluminous mafic volcanism of the Kamchatka back-arc to Miocene (3-6 Ma) and Late Pleistocene to Holocene (< 1 Ma) times. Trace elements and isotopic compositions show that older rocks derived from a depleted mantle through subduction fluid-flux melting (> 20%). Younger rocks form in a back arc by lower melting degrees involving enriched mantle components. The arc front and Central Kamchatka Depression are also underlain by plateau lavas and shield volcanoes of Late Pleistocene age. The focus of these voluminous eruptions thus migrated in time and may be the result of a high fluid flux in a setting where the Emperor seamount subducts and the slab steepens during rollback during terrain accretions. The northern termination of Holocene volcanism locates the edge of the subducting Pacific plate below Kamchatka, a \"slab-edge-effect\" is not observed in the back arc region."],["dc.identifier.doi","10.1007/s00410-009-0447-9"],["dc.identifier.isi","000276276300004"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?goescholar/4176"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19974"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0010-7999"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Mafic Late Miocene-Quaternary volcanic rocks in the Kamchatka back arc region: implications for subduction geometry and slab history at the Pacific-Aleutian junction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","69"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Earth and Planetary Science Letters"],["dc.bibliographiccitation.lastpage","86"],["dc.bibliographiccitation.volume","175"],["dc.contributor.author","Dorendorf, F."],["dc.contributor.author","Wiechert, U."],["dc.contributor.author","Worner, G."],["dc.date.accessioned","2018-11-07T10:57:25Z"],["dc.date.available","2018-11-07T10:57:25Z"],["dc.date.issued","2000"],["dc.description.abstract","Oxygen isotope ratios of olivine and clinopyroxene phenocrysts from the Kluchevskoy volcano in Kamchatka have been studied by CO2 and ArF laser techniques. Measured delta(18)O values of 5.8-7.1 parts per thousand for olivine and 6.2-7.5 parts per thousand for clinopyroxene are significantly heavier than typical mantle values and cannot be explained by crustal assimilation or a contribution of oceanic sediments. Positive correlations between delta(18)O and fluid-mobile elements (Cs, Li, Sr, Rb, Ba, Th, U, LREE, K) and a lack of correlation with fluid-immobile elements (HFSE, HREE) suggest that O-18 was introduced into the mantle source by a fluid from subducted altered oceanic basalt, This conclusion is supported by radiogenic isotopes (Sr, Nd, Pb). Mass balance excludes simple fluid-induced mantle melting. Instead, our observations are consistent with melting a mantle wedge which has been hydrated by O-18-rich fluids percolating through the mantle wedge. O-18-enriched fluids are derived from the subducted oceanic crust and the Emperor seamount chain, which is responsible for a particularly high fluid flux. This hydrated mantle wedge was subsequently involved in are magmatism beneath Kluchevskoy by active intra-are rifting. (C) 2000 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0012-821X(99)00288-5"],["dc.identifier.isi","000085189900006"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11242"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50242"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0012-821X"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","CC BY-NC-ND 3.0"],["dc.rights.uri","http://creativecommons.org/licenses/by-nc-nd/3.0/"],["dc.title","Hydrated sub-arc mantle: a source for the Kluchevskoy volcano, Kamchatka/Russia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","529"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Earth and Planetary Science Letters"],["dc.bibliographiccitation.lastpage","545"],["dc.bibliographiccitation.volume","144"],["dc.contributor.author","Molzahn, M."],["dc.contributor.author","Reisberg, L."],["dc.contributor.author","Wörner, G."],["dc.date.accessioned","2014-12-11T11:16:58Z"],["dc.date.accessioned","2021-10-27T13:13:59Z"],["dc.date.available","2014-12-11T11:16:58Z"],["dc.date.available","2021-10-27T13:13:59Z"],["dc.date.issued","1996"],["dc.description.abstract","Os, Sr, Nd, Pb and O isotopes and trace element data are reported for basaltic andesite and andesite whole rocks and, in part, for selected mineral separates from the Jurassic Ferrar flood basalt province. Radiogenic Sr (> 0.709), unradiogenic Nd (εNd= −3 to −5), and radiogenic Pb isotopes, as well as low Nb/La ratios of 0.4 – 0.6 and Nb/La ratios between 0.45 and 0.6 are found for all rocks including our most primitive sample (Mg# = 71.9). This indicates involvement of either continental crust or enriched lithospheric mantle in magma genesis. 187Re/188Os correlates strongly with 187Os/188Os, with an age of 172 ± 5 Ma, in agreement with published Arsingle bondAr data. Initial 187Os/188Os of 0.194 ± 0.023 is close to the range of typical mantle values for MORB, OIB and lithospheric mantle and much lower than that of continental crust. δ18O values between 5‰ and 7‰ were obtained on fresh bulk samples, separated plagioclases and clinopyroxenes. Srsingle bondO and Srsingle bondOs isotope mixing calculations between depleted mantle peridotite or mantle melts and crustal material rule out assimilation involving basalts with low Os concentrations, and simple binary mixing or pure AFC processes involving picrites. AFC processes, combined with continuous replenishment of picritic magmas, can explain the isotopic data, provided the crustal end-member has high 87Sr/86Sr and low δ18O values. However, lower crustal samples displaying these characteristics are absent in the Ferrar region, and are also unlikely to impart the sediment-like trace element patterns observed in the Ferrar data. A more likely explanation is a lithospheric source enriched by subducted sediments. A contribution to Ferrar magmatism from a plume cannot be distinguished."],["dc.identifier.doi","10.1016/S0012-821X(96)00178-1"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11233"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/91823"],["dc.language.iso","en"],["dc.notes.intern","Migrated from goescholar"],["dc.relation.issn","0012-821X"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","Goescholar"],["dc.rights.access","openAccess"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.subject","Ferrar Group; flood basalts; magma contamination; geochemistry"],["dc.title","Os, Sr, Nd, Pb, O isotope and trace element data from the Ferrar flood basalts, antarctica: evidence for an enriched subcontinental lithospheric source"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","11775"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Scientific Reports"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Gordeychik, Boris N."],["dc.contributor.author","Churikova, Tatiana G."],["dc.contributor.author","Kronz, Andreas"],["dc.contributor.author","Sundermeyer, Caren"],["dc.contributor.author","Simakin, Alexander"],["dc.contributor.author","Wörner, Gerhard"],["dc.date.accessioned","2018-12-18T10:55:41Z"],["dc.date.available","2018-12-18T10:55:41Z"],["dc.date.issued","2018"],["dc.description.abstract","Complex core-rim zoning of Mg-Fe-Ni-Ca-Cr-Al-P in high-Mg olivine crystals from a tuff ring of Shiveluch volcano, Kamchatka, enables reconstruction of the entire olivine crystallization history from mantle conditions to eruption. Bell-shaped Fo86-92 and Ni profiles in crystal cores were formed by diffusion after mixing with evolved magma. Diffusion proceeded to the centres of crystals and completely equilibrated Fo and Ni in some crystals. Diffusion times extracted from Fo and Ni core profiles range from 100 to 2000 days. During subsequent mixing with mafic mantle-equilibrated melt, the cores were partially dissolved and overgrown by Fo90 olivine. Times extracted from Fo and Ni diffusion profiles across the resorption interface between the core and its overgrowth range within 1-10 days, which corresponds to the time of magma ascent to the surface. The overgrowth shows identical smooth Fo-Ni decreasing zoning patterns for all crystals towards the margin, indicating that all crystals shared the same growth history after last mixing event prior to eruption. At the same time, Ca, and to an even greater extent Cr, Al, and P have oscillatory growth patterns in the crystals overgrowth. Our data show that magma ascent can be extremely short during maar/tuff ring eruption."],["dc.identifier.doi","10.1038/s41598-018-30133-1"],["dc.identifier.pmid","30082716"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15442"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/57129"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.relation.eissn","2045-2322"],["dc.relation.orgunit","Fakultät für Geowissenschaften und Geographie"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Growth of, and diffusion in, olivine in ultra-fast ascending basalt magmas from Shiveluch volcano"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","72"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Open Geology Journal"],["dc.bibliographiccitation.lastpage","84"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Tchouankoue, Jean Pierre"],["dc.contributor.author","Wambo, Nicole Armelle Simeni"],["dc.contributor.author","Dongmo, Armand Kagou"],["dc.contributor.author","Wörner, Gerhard"],["dc.date.accessioned","2019-07-09T11:54:39Z"],["dc.date.available","2019-07-09T11:54:39Z"],["dc.date.issued","2012"],["dc.description.abstract","Basaltic dyke swarms in the southern continental part of the Cameroon Volcanic Line (Bangangte, Dschang, Manjo areas) are tholeiitic in composition with 46 to 50 wt.% SiO 2 and have moderate Mg-numbers (53–59), medium TiO 2 contents (1.48–2,05 wt.%), and flat to mildly enriched incompatible trace element patterns. Comparison with trace element patterns of representative Cenozoic basaltic rocks of the Cameroon Volcanic Line (Bana anorogenic complex, Mt. Bambouto, Adamawa Plateau basalts) indicates that these dykes are less enriched in light REE and show different incompatible trace element ratios (La/Yb: 5.7 to 8.6; Zr/Nb: 7.6 to 12.0; Ba/Th: 87.7 to 93.3). The trace element patterns of the dykes and their Sr- and Nd- isotope compositions, however, are similar to those of the pre-Cenozoic volcanic rocks of the Benue Trough in Nigeria. Our data therefore suggest that these dykes represent the magmatic history related to the break-up of Africa and South America and are unrelated to the Tertiary volcanism of the Cameroon Line."],["dc.identifier.doi","10.2174/1874262901206010072"],["dc.identifier.fs","598586"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/9514"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/60702"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.rights","CC BY-NC 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by-nc/3.0"],["dc.title","Petrology, Geochemistry, and Geodynamic Implications of Basaltic Dyke Swarms from the Southern Continental Part of the Cameroon Volcanic Line, Central Africa"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","567"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Geostandards and Geoanalytical Research"],["dc.bibliographiccitation.lastpage","584"],["dc.bibliographiccitation.volume","43"],["dc.contributor.author","Wu, Shitou"],["dc.contributor.author","Wörner, Gerhard"],["dc.contributor.author","Jochum, Klaus Peter"],["dc.contributor.author","Stoll, Brigitte"],["dc.contributor.author","Simon, Klaus"],["dc.contributor.author","Kronz, Andreas"],["dc.date.accessioned","2019-10-10T07:21:46Z"],["dc.date.available","2019-10-10T07:21:46Z"],["dc.date.issued","2019"],["dc.description.abstract","The limit of detection (LOD), ICP mass load effect, downhole induced fractionation and matrix effect of 193 nm ArF excimer laser ablation system at high spatial resolution were systematically investigated. Trace elements in GSD-1G, StHs6/80-G and NIST612 were measured at 10 μm spot size. The results showed that the LOD decreased with the increasing ablation diameter. In addition, the LOD of part of trace elements was in a range of 1–10 μg g−1 at 7 μm spot size. Mass load effect was negatively correlated with the corresponding oxide melting temperature, while positively correlated with the elemental 1st ionization potential. Downhole fractionation was negligible when the ratio of ablation depth to spot size was smaller than 1:1. Matrix effect between NIST610, GSD-1G, ATHO-G and StHs6/80-G did not change in the spot size ranged from 10 μm to 50 μm. The analytical results of GSD-1G, StHs6/80-G and NIST612 at 10 μm spot size matched well with the reference values. Generally, 10 μm spatial resolution could satisfy the requirements of trace elements analysis."],["dc.description.sponsorship","China Scholarship Council http://dx.doi.org/10.13039/501100004543"],["dc.description.sponsorship","National Natural Science Foundation of China http://dx.doi.org/10.13039/501100001809"],["dc.identifier.doi","10.1111/ggr.12301"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16907"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62484"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1639-4488"],["dc.relation.issn","1751-908X"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","The Preparation and Preliminary Characterisation of Three Synthetic Andesite Reference Glass Materials (ARM‐1, ARM‐2, ARM‐3) for In Situ Microanalysis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1487"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Bulletin of Volcanology"],["dc.bibliographiccitation.lastpage","1511"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Kay, Suzanne Mahlburg"],["dc.contributor.author","Coira, Beatriz"],["dc.contributor.author","Woerner, Gerhard"],["dc.contributor.author","Kay, Robert W."],["dc.contributor.author","Singer, Bradley S."],["dc.date.accessioned","2018-11-07T08:49:19Z"],["dc.date.available","2018-11-07T08:49:19Z"],["dc.date.issued","2011"],["dc.description.abstract","The giant ignimbrites that erupted from the Cerro Galan caldera complex in the southern Puna of the high Andean plateau are considered to be linked to crustal and mantle melting as a consequence of delamination of gravitationally unstable thickened crust and mantle lithosphere over a steepening subduction zone. Major and trace element analyses of Cerro Galan ignimbrites (68-71% SiO2) that include 75 new analyses can be interpreted as reflecting evolution at three crustal levels. AFC modeling and new fractionation corrected delta O-18 values from quartz (+7.63-8.85aEuro degrees) are consistent with the ignimbrite magmas being near 50:50 mixtures of enriched mantle (Sr-87/Sr-86 similar to 0.7055) and crustal melts (Sr-87/Sr-86 near 0.715-0.735). Processes at lower crustal levels are predicated on steep heavy REE patterns (Sm/Yb = 4-7), high Sr contents (> 250 ppm) and very low Nb/Ta (9-5) ratios, which are attributed to amphibolite partial melts mixing with fractionating mantle basalts to produce hybrid melts that rise leaving a gravitationally unstable garnet-bearing residue. Processes at mid crustal levels create large negative Eu anomalies (Eu/Eu = 0.45-0.70) and variable trace element enrichment in a crystallizing mush zone with a temperature near 800-850A degrees C. The mush zone is repeatedly recharged from depth and partially evacuated into upper crustal magma chambers at times of regional contraction. Crystallinity differences in the ignimbrites are attributed to biotite, zoned plagioclase and other antecrysts entering higher level chambers where variable amounts of near-eutectic crystallization occurs at temperatures as low as 680A degrees C just preceding eruption. Ar-40/Ar-39 single crystal sanidine weighted mean plateau and isochron ages combined with trace element patterns show that the Galan ignimbrite erupted in more than one batch including a similar to 2.13 Ma intracaldera flow and outflows to the west and north at near 2.09 and 2.06 Ma. Episodic delamination of gravitationally unstable lower crust and mantle lithosphere and injection of basaltic magmas, whose changing chemistry reflects their evolution over a steepening subduction zone, could trigger the eruptions of the Cerro Galan ignimbrites."],["dc.identifier.doi","10.1007/s00445-010-0410-7"],["dc.identifier.isi","000297708400004"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7133"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21434"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0258-8900"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Geochemical, isotopic and single crystal Ar-40/Ar-39 age constraints on the evolution of the Cerro Galan ignimbrites"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]